SciClone Pharmaceuticals, Inc. announced today that a new
intent-to-treat meta-analysis of three clinical trials indicates
that combination therapy with ZADAXIN thymosin alpha 1 and
interferon produced a higher end of treatment response in hepatitis
C patients than interferon alone.

SAN MATEO, Calif., Dec. 23, 1998 /PRNewswire/ -- SciClone
Pharmaceuticals, Inc. announced today that a new intent-to-treat
meta-analysis of three clinical trials indicates that combination
therapy with ZADAXIN thymosin alpha 1 and interferon produced a
higher end of treatment response in hepatitis C patients than
interferon alone. Kenneth Sherman, M.D., Ph.D., Associate Professor
of Medicine and Director of Clinical Trials -- Liver Unit of the
University of Cincinnati Medical Center, presented the
meta-analysis at the 2nd International Conference on Therapies for
Viral Hepatitis in Hawaii.

The meta-analysis combined data from three clinical trials
involving a total of 121 patients, including difficult to treat
patients such as cirrhotics and interferon failures. The patients
were given either interferon in combination with thymosin alpha 1
(n=67) or interferon alone (n=54). The intent-to-treat
meta-analysis revealed an end of treatment response, defined as
normalization of ALT (a measurement of liver inflammation), of
44.7% among patients receiving the combination regimen and 22.2%
among patients receiving interferon alone (p=0.0096). Sustained
response occurred in 15/67 (22.3%) of thymosin alpha 1/interferon
treated patients and only 5/54 (9.26%) of those patients treated
with interferon alone (p=0.1). The meta-analysis also demonstrated
that patients who received the combination regimen did not
experience increased or new side effects compared to side effects
related to interferon alone.

``ZADAXIN appears to enhance significantly the activity of
interferon in treating hepatitis C,'' Dr. Sherman commented. ``By
combining the two drugs, we may be able to improve treatment
efficacy without increasing adverse effects associated with
interferon monotherapy. Pivotal combination studies are clearly
warranted,'' he added.

``These data confirm earlier study results and illustrate that
ZADAXIN is an important new treatment for hepatitis C,'' stated
Alfred Rudolph, M.D., SciClone's Chief Operating Officer.
``Clinical data continue to confirm that ZADAXIN is an effective
therapy for viral hepatitis with a unique safety profile.''

ZADAXIN is an immunomodulator approved and marketed for
treatment of chronic hepatitis B in the People's Republic of China,
the Republic of the Philippines and Singapore. SciClone has filed
for approval to market ZADAXIN for this indication in 16 additional
countries.

The World Health Organization and the Centers for Disease
Control and Prevention estimate that over 100 million people
worldwide are infected with the chronic hepatitis C virus. In the
United States alone, over 4 million people are infected with the
virus, and there are over 170,000 new cases per year.

SciClone Pharmaceuticals, Inc. is an international
biopharmaceutical company that acquires, develops and
commercializes specialist-oriented drugs for treating chronic and
life-threatening diseases for which there are no adequate treatment
modalities, including hepatitis B, hepatitis C, cancer, immune
system disorders, and cystic fibrosis. The company's second lead
product candidate, CPX, is in a phase I/II trial for cystic
fibrosis.

Press releases and corporate information from SciClone
Pharmaceuticals, Inc. are available on the Internet at
www.sciclone.com and by fax at 800-996-7256.

The statements made in this press release contain certain
forward-looking statements that involve a number of risks and
uncertainties, including, without limitation, those associated with
the initiation and success of phase III clinical trials. Actual
events or results may differ from the Company's expectations and
beliefs. Factors which may affect the actual results achieved by
the Company include future actions by the FDA, or equivalent
regulatory authorities in foreign countries, results of pending or
future ZADAXIN clinical trials, as well as risk factors listed from
time to time in SciClone's SEC filings and reports, including, but
not limited to, its Annual Report on Form 10-K.